Apparently, negotiations are underway with Harrison Ford (Hans Solo), Mark Hammill (Luke Skywalker) and Carrie Fisher (Princess Leia) to coax them into reprising their roles for the upcoming trilogy. Two sources claim that Ford is already signed up but it's much too early to commit to anything definite. It would seem that Disney/Lucasfilm is still in control of the fates of these actors. They'll either do the first film (at least) or they'll be written out.
According to Hammill, he has been invited to meet the writers and discuss the part but hasn't actually met any of the powers that be as yet. He admits that things are undersandably chaotic at the studios right now due to the recent acquisition of the rights and the transfer of power from George Lucas to J.J. Abrams.
In a move that is certain to help settle things down, Kathleen Kennedy is stepping into her position as co-chairman of Lucasfilm. This means she is stepping away from her producing partner Stephen Spielberg and the production of "Jurassic Park 4". Spielberg will carry on with Frank Marshall, Kennedy's other partner, but will not take over as director.
As chaotic as things must be at Disney/Lucasfilm, Kennedy's presence will be a calming influence. She has worked on films such as "E.T.", "Twister", "The Sixth Sense" and "War of the Worlds" (among many others) and those films turned out to be winners. With a director like Abrams, there's no reason to fear that the chaos will not last long. If it's meant to be that Ford, Hammill and Fisher will return, it'll happen.
Another interesting situation involves the fact that John Williams, composer extraordinaire, is willing and ready to return to compose the music. It seems fitting since he's scored all six "Star Wars" films already but there's a chance that Abrams might want to work with Michael Giacchino again. Giacchino scored "Lost", "Alias" and "Fringe", all Abrams' productions, as well as "Star Trek", "Super 8" and several other Abrams' films. His music is as powerful, lush and emotional as Williams' so it could be very interesting--especially if it ends up being a sort of super-collaboration.
Stay tuned for more details as they become available.